1. Field of the Invention
The present invention relates to a GSM terminal, and more particularly, to an apparatus and method for identifying a SIM (Subscriber Identify Module) card owner in a GSM terminal.
2. Background of the Related Art
Generally, a Global System for Mobile communication (GSM) terminal using a time division multiple connection method uses Subscriber Identity Module (SIM) cards. The SIM card is a removable smart card comprised of a microprocessor and a memory chip. In the memory chip, personal information of a SIM card owner and other information, including (phone numbers and network numbers) are stored. In addition, personal certification information such as a Personal Identification Number SPIN) and a Personal Unblocking Key (PUK) of the SIM card owner are stored.
Personal certification information stored in the memory chip enables verification of the SIM card owner by determining whether the SIM card owner is registered for the network when the SIM card is inserted into the mobile communication terminal. Typically, after inserting the SIM card in the GSM terminal, the user inputs his or her PIN. Then, the microprocessor determines whether the SIM card owner is a registered user by comparing the PIN entered by the user with the PIN stored in the memory chip. If the two PINs match, the microprocessor permits the user access to the GSM terminal. If the two PINs are different, the microprocessor blocks the use of the terminal. If the user fails to enter the correct PIN in three attempts, the user must then enter the PUK in order to release the blocking of the terminal.
In the prior art systems, there was no way to verify the SIM card owner other than by inserting SIM into a GSM terminal, turning on the terminal power and entering the PIN. Moreover, it has been virtually impossible to identify one's own SIM card with the naked eye because all SIM cards are basically identical in appearance.